How does object and pattern recognition work?
- Both has very complex systems
- Pattern recognition is alot about “problem solving”
- Uses both bottom-up processes and top-down processes
Perceptual organization
How we divide a visual scene into individual objects and organize seperate parts of what we see into something meanful
- A telephone looking like one
Feature detection
How we can recognize visual stimulus as familiar pattern
- Where letters mean something
- Detect small features first, then put them into a “whole”
Gestalt psychology
- Principles that describes the regularities according to which we grup visual input
- The whole part is different than the sum of its parts
How we percieve objects
Figure-ground principle
- One part figure and the other is a background
Vase-two faces picture
Closure principle
Filling the gaps in a line or something, to make sense of it
Proximity principle
Whats near tend to be grouped together, in perception
Similarity principle
Visually similar, same color or texture
Good continuation principle
The dots or lines continues in a similar fashion
- Assuming smooth lines
Common fate principle
Enteties that move together are perceptually grouped together
- Such as movement
Simplicity principle
Elements that are parts of a pattern tends to get grouped together
- Similarity
- Continuity
- What patterns you see instantly when looking at a pattern
What belongs together?
How can we recongnize a visual stimulus as a familiar pattern?
- Detection of simple features
Different types of lines that form certain letters
Pandemonium model
A very bottum-up processing
- Different types of demons
Mental mechanisms that process stimulus
- The demon that screams the most has the “accurate” feauture to what we are seeing
What are keypoints from the pandemonium model?
- Parallel processes
More than one process at a time trying to figure out the pattern - Stimulus driven detection
- Problem solving approach
Feature detectors
- Specialized cells for various visual features and patterns
- Neurological differences
Is pattern recongnition purely bottom-up process?
- No, it doesnt explain everything
- Context matters
Same looking symbol/letter can be a different letter in different words - Prior knowledge, expectations
Connectionist model - Pattern recognition
- For words
- Input units
Responds to different features - Hidden units
Internal process, find connection between input units where positive activation leads to - Output units
What we perceive as words - Top-down process
Some spelling patterns more likely than others
Expectations on what letter comes afterwards
Repetition Blindness
Tendency to not percieve a pattern when its quickly repeated
Misreading Effect
Tendency to read a word that is not there but should due to context.
What does Muller-Lyer visual illusion arise from?
Culture differences
- People who has been brought up in areas where corners of building are often lacking feel like the two lines are similar in length
- Good continuation
